Printing cylinders



July 17, 1956 J. WlRTH 2,754,849

PRINTING CYLINDERS Filed June 16, 1953 IN V EN TOR. JoJ'EF M United States Patent PRINTING CYLINDERS Josef Wirth, Celle, Germany Application June 16, 1953, S erial'No. 362,101 Claimspriority, application Germany June 19 1952 17 Claims. (Cl. 138-79) The present invention relates to printing cylinders, and

It is another object of the present invention to reduceor eliminate the influence of the moisture to which the cylinder is exposed during the individual printing operations.

It is a further object of the present invention to avoid the drawbacks of the known cylinders in relation to the durability and service life thereof.

It is still another object of the present invention to avoid the waste of timber encountered with the known types of cylinders.

A cylinder for printing patterns on wallpaper, linoleum or the like according to the present invention comprises a substantially cylindrical body consisting of natural wood and having a heart-wood portion and a sap-wood portion surrounding the heart-wood portion, the heart-wood portion having a substantially cylindrical, preferably centra'lly arranged bore, the cylindrical body having a plurality of preferably symmetrically arranged radial cuts, at least one of the cuts extending from the cylindrical sur face of the body to the cylindrical, centrally arranged bore.

In an embodiment of the present invention filling materials are arranged, respectively, in the cuts, the filling materials consisting of wood particles having substantially the same structure as the body surrounding the cuts.

Preferably binding materials are arranged in the cuts and hold, respectively, the filling materials in the cuts.

In one embodiment of the present invention part, for instance one of the cuts extends from the cylindrical surface of the body through the sap-wood portion to the cylindrical, centrally arranged bore of the heart-wood portion, the other ones of the cuts extending from the cylindrical surface of the body through the sap-wood portion to points in the l'IELIIFWOO'd portion being distances apart from the bore of the heart-wood portion.

ln a preferred embodiment of the present invention the cuts-extending to the bore of the heart-Wood portion have enlarged end portions arranged in the heart-wood portion and opening into "the bore, and outer portions communicating, respectively, with the enlarged end portions, the enlarged end portions being filled by a preferably bituminous material so as to allow a deformation of the same by entering the cylindrical bore of the heartwood portion.

The present invention will'now be more fully described with reference to the accompanying drawings in which:

2,754,8'49 Patented July 17, 1956 Fig. l-show's a cross-section of a printing cylinder known in the art;

Fig; 2 shows across-section of a cylinder according to a first embodiment of the present invention;

Fig. 3 is a side view of the cylinder shown in Fig. 2;

Fig; 4- shows an exploded cross-section of a cylinder according to another embodiment of thepresent invention; and

Fig. 5 shows an exploded half cross-section of a cylinder according to still another embodiment of the present invention;

Referring now to the drawings and first to Fig. 1 showinga cross-section of a printing cylinder known in the art, itwill be seen that the cylinder is composed of a plurality of segments or sectors 1 which are put together as clearly shown in Fig. 1, without regard to the structure of the segments so that the structure of the cylinder as a whole is non-uniform; inside the cylinder as well as on the surface thereof. Particularly the fact that the surface of the roller or cylinder has diflerent properties changing from segment to segment, renders the applica' tion of printing patterns difiicult and leads to a non-uniform wear of the surface of the cylinder so that a uniform printing is unattainable after a relatively short period of use.

Furthermore, the unequal structure of the wood leads to tensions in the segments which dilfer greatly from one another.

Also the moisture to which the cylinder is exposed during the individual steps of operation changes greatly from segment to segment since the amount of water taken up by the individual segments varies from segment to segment. Naturally the sap-wood portions of the cylinder take up a larger amount of moisture than those taken up by the heart-wood portions so that a relative deformation of the individual wood parts with respect to one another occurs. This is particularly disadvantageous if sap-wood and heart-wood portions of different sectors are arranged close to one another as shown in Fig. 1 because considerable tensions are caused thereby.

Referring now to Figs. 2 and 3 of the drawings showing a first embodiment according to the present invention, it will be seen that the wood structure is uniform in the interior as well as on the surface, i. e. the same ratio of sapwood 2 to heart-wood 3 is maintained over the entire length and cross-section of the cylinder. Thus, the wood structure generated by the natural growth remains completely unaltered. 4 is a cut extending from the cylindrical surface of the body through the sap-wood portion 2 to a cylindrical, centrally arranged bore 6 of the heart-wood portion 3. 5 are cuts extending from the cylindrical surface of the body through the sap-wood portion 2 to points in the heart-wood portion 3 which are preferably equal distances apart from the bore 6 of the heart-wood portion 3.

The cuts 4 and 5 reduce very much the tensions arising in the wood during drying and anticipate, as it were, the longitudinal cracks which normally arise during drying. Also these cuts 4 and 5 accelerate the drying process since they contribute to a quicker removal of the moisture from the interior parts of the timber to the outer parts.

After the finishing of the artificial drying the interstices generated by the deep and shallow cuts 4 and 5 are filled by wood particles 9 having approximately the same structure as .the body, and of a binding material (not shown) .such as a glue or a cement. The wood particles 9 are preferably .made from the same tree trunk from which the cylindrical body .is cut. ,In this way it is accomplished that the finished cylinder is thoroughly homogeneous so that the moisture attacks the cylinder in a perfect uniform manner, during the use of the cylind r as well as during storage thereof.

A further advantage of a cylinder according to the present invention consists in a uniform distribution of the weight over the entire length of the cylinder or roller so that the longitudinal line of gravity thereof practically coincides with the longitudinal median of the bore. In this way a uniform, non-oscillating running of the roller is secured so that a much higher speed of rotation thereof is applicable and yet a higher preservation of the printing machines is achieved. Thus it will be understood that a roller according to the present invention is practically the equivalent of a balanced rotating roller.

Referring now to Fig. 4 the cylinder is divided by cuts into four equal sectors. The cylinder could be subdivided into six, eight or more parts or sectors, the number of the parts and the subdivision of the curved surface of the cylinder depending on the diameter thereof and increasing with the same. The individual parts of the cylinder are dried and then put together with the cutting faces 7 such as are generated during the cutting up of the cylinder in contact with one another. Preferably each part or segment is marked before the cylinder is cut into segments. The uniformity or equality of structure is preserved after the segments have been reassembled and glued, the insertion of wood particles being omitted in this embodiment.

Referring now to the embodiment shown in Fig. 5, the faces 7 of the cuts have recesses 8 provided in the heartwood portions, and forming enlarged end portions opening into the bore 6. The enlarged end portions are filled, after the gluing together of the sap-wood portions, with hot bitumen or the like which does not harden so that the heart-wood portions can be deformed without incurring undesirable tensions therein, it being well known that the heart-wood undergoes greater deformations than the sap-wood portion. Such a filling with bituminous material is particularly advantageous with cylinders having a large diameter in which the heart-wood has a relatively larger proportion than in cylinders having a small diameter. If as a consequence of a deformation of the timber part of the bitumen escapes the enlarged end portions it can enter the bore 6, at the same time taking the appearance of a welding seam.

While I have shown and described my invention in connection with a cylinder for printing patterns on wallpaper, linoleum, or the like, it should be understood that I do not wish to be limited to such application since my invention may be equally adaptable to various other structures without departing from the spirit of my invention.

What I wish to secure by Letters Patent is:

l. A cylinder for printing patterns on wallpaper, linoleum and the like, comprising, a substantially cylindrical body consisting of natural wood and having a heart-wood portion and a sap-wood portion surrounding said heartwood portion, said heart-wood portion having a substantially cylindrical bore, said cylindrical body having a plurality of radial cuts, at least one of said cuts extending from the cylindrical surface of said body to said cylindrical bore, said cuts being filled with wood particles having substantially the same structure as said body surrounding said cuts.

2. A cylinder for printing patterns on wallpaper, linoleum and the like, comprising, a substantially cylindrical body consisting of natural wood and having a heart-wood portion and a sap-wood portion surrounding said heartwood portion, said heart-wood portion having a substantially cylindrical centrally arranged bore, said cylindrical body having a plurality of symmetrically arranged radial cuts, at least one of said cuts extending from the cylindrical surface of said body to said cylindrical centrally arranged bore, said cuts being filled by a mixture of wood particles with a binder, said wood particles having substantially the same structure as said body surrounding said cuts. 1

3. A cylinder for printing patterns on wallpaper, linoleum and the like, comprising, in combination, a substantially cylindrical body consisting of natural wood and having a heart-wood portion and a sap-wood portion surrounding said heart-wood portion, said heart-wood portion having a substantially cylindrical centrally arranged bore, said cylindrical body having a plurality of symmetrically arranged radial cuts, at least one of said cuts extending from the cylindrical surface of said body to said cylindrical centrally arranged bore; and filling materials arranged, respectively, in said cuts, said filling materials consisting of wood particles having substantially the same structure as said body surrounding said cuts.

4. A cylinder for printing patterns on wallpaper, linoleum and the like, comprising, in combination, a substantially cylindrical body consisting of natural wood and having a heart-wood portion and a sap-wood portion surrounding said heart-wood portion, said heart-wood portion having a substantially cylindrical centrally arranged bore, said cylindrical body having a plurality of symmetrically arranged radial cuts, at least one of said cuts extending from the cylindrical surface of said body to said cylindrical centrally arranged bore; filling materials arranged, respectively, in said cuts, said filling materials consisting of wood particles having substantially the same structure as said body surrounding said cuts; and binding materials arranged in said cuts and holding, respectively, said filling materials in said cuts.

5. A cylinder for printing patterns on wallpaper, linoleum and the like, comprising, a substantially cylindrical body consisting of natural wood and having a heart-wood portion and a sap-wood portion surrounding said heartwood portion, said heart-wood portion having a substantially cylindrical centrally arranged bore, said body having a plurality of symmetrically arranged, radial cuts, part of said cuts extending from the cylindrical surface of said body through said sap-wood portion to said cylindrical, centrally arranged bore of said heart-wood portion, said cuts being filled with wood particles having substantially the same structure as said body surrounding said cuts, the other ones of said cuts extending from said cylindrical surface of said body through said sap-wood portion to points in said heart-wood portion being distances apart from said bore of said heart-wood portion.

6. A cylinder for printing patterns on wallpaper, linoleum and the like, comprising, in combination, a substantially cylindrical body consisting of natural wood and having a heart-wood portion and a sap-wood portion surrounding said heart-wood portion, said heart-wood portion haV ing a substantially cylindrical centrally arranged bore, said cylindrical body having a plurality of symmetrically arranged radial cuts, part of said cuts extending from the cylindrical surface of said body through said sap-wood portion to said cylindrical, centrally arranged bore of said heart-wood portion, the other ones of said cuts extending from said cylindrical surface of said body through said sap-wood portion to points in said heart-wood portion being distances apart from said bore of said heart-wood portion; and filling materials arranged, respectively, in said cuts, said filling materials consisting of wood particles having substantially the same structure as said body surrounding said cuts.

7. A cylinder for printing patterns on Wallpaper, linoleum and the like, comprising, in combination, a substantially cylindrical body consisting of natural wood and having a heart-wood portion and a sap-wood portion surrounding said heart-wood portion, said heart-wood portion having a substantially cylindrical centrally arranged bore, said cylindrical body having a plurality of symmetrically arranged radial cuts, part of said cuts extending from the cylindrical surface of said body through said sap-wood portion to said cylindrical, centrally arranged bore of said heart-wood portion, the other Ones of said cuts extending from said cylindrical surface of said body through said sap-wood portion to points in said heart-wood portion being distances apart from said bore of said heart-Wood portion; filling materials arranged, respectively, in said cuts,

said filling materials consisting of wood particles having substantially the same structure as said body surrounding said cuts; and binding materials arranged in said cuts and holding, respectively, said filling materials in said cuts.

8. A cylinder for printing patterns on wallpaper, linoleum and the like, comprising, a substantially cylindrical body consisting of natural wood and having a heartwood portion, and a sap-wood portion surrounding said heartwood portion, said heart-Wood portion having a substantially cylindrical centrally arranged bore, said body having a plurality of symmetrically arranged, radial cuts, one of said cuts extending from the cylindrical surface of said body through said sap-wood portion to said cylindrical, centrally arranged bore of said heart-wood portion, the other ones of said cuts extending from said cylindrical surface of said body through said sap-wood portion to points in said heart-wood portion, said cuts being filled with wood particles having substantially the same structure as said body surrounding said cuts being distances apart from said bore of said heart-Wood portion.

9. A cylinder for printing patterns on wallpaper, linoleum and the like, comprising, a substantially cylindrical body consisting of natural wood and having a heart-wood portion, and a sap-wood portion surrounding said heartwood portion, said heart-Wood portion having a substantially cylindrical centrally arranged bore, said body having a plurality of symmetrically arranged, radial cuts, one of said cuts extending from the cylindrical surface of said body through said sap-wood portion to said cylindrical, centrally arranged bore of said heart-wood portion, the other ones of said cuts extending from said cylindrical surface of said body through said sap-wood portion to points in said heart-wood portion being distances apart from said bore of said heart-wood portion; and filling materials arranged, respectively, in said cuts, said filling materials consisting of wood particles having substantially the same structure as said body surrounding said cuts.

10. A cylinder for printing patterns on wallpaper, linoleum and the like, comprising, a substantially cylindrical body consisting of natural wood and having a heart-wood portion, and a sap-wood portion surrounding said heartwood portion, said heart-wood portion having a substantially cylindrical centrally arranged bore, said body having a plurality of symmetrically arranged, radial cuts, one of said cuts extending from the cylindrical surface of said body through said sap-wood portion to said cylindrical, centrally arranged bore of said heart-Wood portion, the other ones of said cuts extending from said cylindrical surface of said body through said sap-wood portion to points in said heart-wood portion being distances apart from said bore of said heart-wood portion; filling materials arranged, respectively, in said cuts, said filling materials consisting of wood particles having substantially the same structure as said body surrounding said cuts; and binding materials arranged in said cuts and holding, respectively, said filling materials in said cuts.

11. A cylinder for printing patterns on wallpaper, linoleum and the like, comprising, a substantially cylindrical body consisting of natural wood and having a heart-wood portion and a sap-wood portion surrounding said heartwood portion, said heart-wood portion having a substantially cylindrical centrally arranged bore, said body having a plurality of symmetrically arranged, radial cuts, said cuts extending from the cylindrical surface of said body through said sap-wood portion to said cylindrical, centrally arranged bore of said heart-wood portion, said cuts being filled by a mixture of Wood particles with a binder, said wood particles having substantially the same structure as said body surrounding said cuts.

12. A cylinder for printing patterns on wallpaper, linoleum and the like, comprising, in combination, a substantially cylindrical body consisting of natural wood and having a heart-wood portion and a sap-wood portion surrounding said heart-wood portion, said heart-wood portion having a substantially cylindrical centrally arranged bore, said cylindrical body having a plurality of symmetrically ar-' ranged radial cuts, said cuts extending from the cylindrical surface of said body through said sap-wood portion to said cylindrical, centrally arranged bore of said heart-wood portion; and filling materials arranged, respectively, in said cuts, said filling materials consisting of wood particles having substanttially the same structure as said body surrounding said cuts.

13. A cylinder for printing patterns on wallpaper, linoleum and the like, comprising, in combination, a substantially cylindrical body consisting of natural wood and having a heart-Wood portion and a sap-wood portion surrounding said heart-wood portion, said heart-wood portion having a substantially cylindrical centrally arranged bore, said cylindrical body having a plurality of symmetrically arranged radial cuts, said cuts extending from the cylindrical surface of said body through said sapwood portion to said cylindrical, centrally arranged bore of said heart-wood portion; filling materials arranged, respectively, in said cuts, said filling materials consisting of wood particles having substantially the same structure as said body surrounding said cuts; and binding materials arranged in said cuts and holding, respectively, said filling materials in said cuts.

14. A cylinder for printing patterns on wallpaper, linoleum and the like, comprising in combination, a substantially cylindrical body consisting of natural wood and having a heart-wood portion and a sap-Wood portion surrounding said heart-wood portion, said heartwood portion having a substantially cylindrical centrally arranged bore, said cylindrical body having a plurality of symmetrically arranged radial cuts, at least part of said cuts extending from the cylindrical surface of said body through said sap-wood portion to said cylindrical, centrally arranged bore of said heart-wood portion, said cuts extending to said bore of said heart-wood portion having enlarged end portions opening into said bore, said outer portions communicating, respectively, with said enlarged end portions; binding materials arranged in said cuts except said enlarged end portions thereof; and a material filling said enlarged end portions of said cuts and allowing a deformation of the same by entering said cylindrical bore of said heart-wood portion.

15. A cylinder for printing patterns on Wallpaper, linoleum and the like, comprising in combination, a substantially cylindrical body consisting of natural wood and having a heart-wood portion and a sap-wood portion surrounding said heart-wood portion, said heart-wood portion having a substantially cylindrical centrally arranged bore, said cylindrical body having a plurality of symmetrically arranged radial cuts, at least part of said cuts extending from the cylindrical surface of said body through said sap-wood portion to said cylindrical, centrally arranged bore of said heart-wood portion, said cuts extending to said bore of said heart-wood portion having enlarged end portions arranged in said heart-Wood portion and opening into said bore, said outer portions communicating, respectively, with said enlarged end portions; binding materials arranged in said cuts except said enlarged end portions thereof; and a material filling said enlarged end portions of said cuts and allowing a deformation of the same by entering said cylindrical bore of said heart-wood portion.

16. A cylinder for printing patterns on wallpaper, linoleum and the like, comprising, in combination, a substantially cylindrical body consisting of natural wood and having a heart-wood portion and a sap-Wood portion surrounding said heart-wood portion, said heart-Wood portion having a substantially cylindrical centrally arranged bore, said cylindrical body having a plurality of symmetrically arranged radial cuts, at least part of said cuts extending from the cylindrical surface of said body through said sap-wood portion to said cylindrical, centrally arranged bore of said heart-wood portion, said cuts extending to said bore of said heart-wood portion having enlarged end portions opening into said bore, said outer portions communicating, respectively, with said enlarged end portions; binding materials arranged in said cuts except said enlarged end portions thereof; and a bituminous material filling said enlarged end portions of said cuts and allowing a deformation of the same by entering said cylindrical bore of said heartwood portion.

17. A cylinder for printing patterns on wallpaper, linoleum and the like, comprising, in combination, a substantially cylindrical body consisting of natural wood and having a heart-wood portion and a sap-wood portion surrounding said heart-wood portion, said heartwood portion having a substantially cylindrical centrally arranged bore, said cylindrical body having a plurality of symmetrically arranged radial cuts, at least part of said cuts extending from the cylindrical surface of said body through said sap-wood portion to said cylindrical, centrally arranged bore of said heart-wood portion, said cuts extending to said bore of said heart-wood portion having enlarged end portions arranged in said heart-wood portion and opening into said bore, said outer portions communicating, respectively, with said enlarged end portions; binding materials arranged in said cuts except said enlarged end portions thereof; and a bituminous material filling said enlarged end portions of said cuts and allowing a deformation of the same by entering said cylindrical bore of said heart-wood portion.

References Cited in the file of this patent FOREIGN PATENTS 52,779 Germany July 14, 1890 219,099 Germany Feb. 16, 1910 626,185 France May 7, 1927 628,157 France June 21, 1927 

